Internal-combustion engine



May s, 1928. 1,669,093 E. KRETTINGEN INTERNAL COMBUSTION ENGINE Filed March 30. 1926 2 Sheets-Sheet 1 May s, 1928.

E. KRETT INGEN INTERNAL COMBUSTION ENGINE Filed March 50. 1926 2 Sheets-Sheet 2 Patented May 8, 1928.

UNITED STATES EMIANUEL KRETTINGEN, 03 LOS ANGELES, GALIFQBNIL INTERNAL-COMBUSTION ENGINE.

Application filed March 30, 1926. Serial Re. 98,491..

This invention relates to improvements in internal combustion engines, and particularly to that class of internal combustion engines commonly known as Diesel'engines.

An object of this invention, is to provide an improved internal combustion engine having a pre-combustion chamber and which has an improved construction for discharging or spraying the fuel into the m pre-combustion c amber.

Another object of this invention is to provide a nozzle of simple yet durable construction which will efliciently spray the fuel into the pre-combustion chamber in the form of a solid conical spray, as distinguished from hollow conical spraysproducedi-by the prior nozzles.

A further object of this invention is to provide an improved neck or choke which conveys fuel or gases from the pre-combus tion chamber to the working cylinder of the engine.

With the foregoing and other objects in view, which will be made manifest in the following detailed description and specifically pointed out in the appended claim, reference is had'to the accompanying drawings for an illustrative embodiment of the invention, wherein:

Figure 1 is a vertical section through a working cylinder of the improved internal combustion engine,

Fig. 2 is a vertical section taken on the line 2-2 of Fig. 1,

Fig.- 3 is a top plan view of one of the parts "forming the improved nozzle,

Fig. 4 is a side elevation of the same,

Fig. 5 is a bottom plan view of the part shown in Fig. 3,

Fig. 6 is a vertical section taken on the line 6-6 of Fig. 5,

Fig. 7 is a top plan view of the other part forming the improved nozzle,

Fig. 8 is a vertical section taken on the line 8-8 of Fig. 7, and

Fig. 9 is a horizontal section taken on the line 99 of Fig. 2.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, the cylinder block of the engine'is indicated at 10 providing a working cylinder 11 in which a piston 12 is reciprocable. On top of the cylinder block 10 there is mounted W the cylinder head 13 in which is formed apre'combustion chamber 14 which is conventionally employed upon many types of engines of this class. In the top of the cylinder head 13 there is formed a threaded aperture arranged directl above the center of the pre-combustion c amber 14-, and a tubular member 15 is screwed into the aperture forming part of an inlet valve casing. A second tubular member 16 is threaded into the tubular member 15 and forms another part of the inlet valve casing. The second tubular member 16 is connected to a fuel supply line 17 as by coupling members 18 and 19.

In the second tubular member 16 there is formed an axial bore 20 having its lower end' enlarged, as indicated at 21, receiving a valve stem 22 of an inlet valve 23. A. valve seat member 24 provides a seat for the valve 23 and has a tubular portion 25 extending upwardly within the enlarged end 21 of the bore 20. The tubular portion 25 forms a spring seat for a coil spring 26 and the upper end of the coil spring seats upon a nut 27 mounted upon the upper end of the valve stem 22. The compression of the coil spring 26 urges the valve 23 intoseating position against the valve seat member 24, as is conventional. Fuel entering through the fuel line 17 and through the bore 20 can pass down through the tubular portion 25 of the valve seat member-24 because of flats 28 formed on the lower portion of the valve stem 22. The above described construction is somewhat conventional upon internal combustion engines and it will be readily understood that other constructions may be employed equally as well.

One feature of the invention consists in the nozzle which handles the fuel after it has passed by the valve 23 and before the fuel enters the pre-combustion chamber 14. In the preferred form of construction this nozzle consists of a cup having a bottom 29 and sides 30 besides being provided with an annular flange 31 which rests upon a shoulder formed within the tubular member 15. Centrally of the bottom 29 of this cup there is formed a conical aperture 32 for a purpose hereinafter to be described. The other member which cooperates with the cup to form the nozzle is shown in Figs. 3 to 6 inclusive and has a top 33 and a depending cylindrical part 34. The cylindrical part 34 is slightly reduced in diameter adjacent the top 33, as indicated at 35, and has a plurality of vertical channels 36 formed upon it. Centrally of the bottom of this part there is formed a circular recess 37 preferably having a fiat top, as clearl shown in Fig. 6. Channels 38 are forme upon the bottom of this part and these channels connect the channels 36 with the recess 37 and are so arranged as to be tangential of the recess 37. Small holes 39 are drilled in the top vertically above the channels 36. As clearly shown in Fig. 2, the depending c lindrical portion of the part shown in igs. 3 to 6 inclusive fits snugly within the on shown in Figs. 7 and 8.

e operation of the above described construction is as follows: The fuel is supplied to the engine in the conventional manner, and after passing the inlet valve 23 the 1 fuel flows downwar y through the apertures or holes 39 entering the annular chamber provided by the groove 35 within the cup. The fuel then is caused to flow downwardly through the channels 36 because of the factthat the exterior surface of the cylindrical portion of the upper part of the nozzle fits within the cup, The fuel on flowing downwardly through the channels 36 is caused to enter the channels 38 and to flow into the recess 37, which provides a chamber in the inlet passage to the engine, the bottom of the chamber being provided by the bottom 29 of the cup. The fuel on entering the recess 37 in a tangential manner is caused to whirl in a circular fashion, and while whirling, it passes through the conical aperture 32 and discharged into the pre-combustion chamber 14. As the fuel is whirling While it is passing through the conical aperture 32, the fuel is discharged into the pre-combustion chamber 14 in the form of a solid conical spray, as distinguished from a hollow comcal s ray, thus causin the fuel to be well istributed throu T1 the pre-combustion chamber 14. The uel on entering the pre-combustion chamber 14 through the nozzle outlet will continue to whirl and thus become thoroughly distributed throughout the. pre-combustion chamber. A. neck 40, threaded into the cylinder. head 13, establishes a passage between the working cylinder and the preeombustion chamber 14. The neck 40 has the bore therethrough adjacent its upper end fairly large, as indicated at 41, and adjacent the lower end of the neck there is formed an internal annular shoulder 42 defining a comparatively small aperture or throat. From this internal shoulder the interior surface of the neck is beveled downwardly forming a frusto-conical surface from the shoulder to the bottom of the neck. The purpose of this particular construction is to have the neck self-cleanir. by means of the gases passing therethroug so that there is no danger of the passa e in the neck becoming clogged up. On t e upper stroke of the piston 12 air containing oxygen is being compressed and is being forced from the working cylinder through the neck 40 into the pre-combustion chamber 14. Because oped, only a portion of the fuel burns. This increases the pressure within the pre-combustion chamber 14 and causes the remainder or.the unburnt fuel to be forced from the pre-combustion chamber into the working cylinder, Because of this, the unburnt fuel is forced from the pre-oombustion chamher through a relatively small passage and enters the working cylinder comparatively gradually. Consequently, there is a grad-- ual oxidation of the fuel in the working cylinder which occurs during the downward stroke of the piston and this comparatively gradual combustion does not produce a shock of explosion upon the piston.

A second feature of this invention resides in extending the lower end of the neck 40 so that the lower end of the neck extends materially into the top of the workingcylinder 11. This enables the fuel passing from the pre-combustion chamber 14 to be discharged directly against the top of the piston 12, which will be at the top of its stroke when fuel starts to pass from the precombustion chamber 14. The piston 12 at this instant provides a bafile against which the fuel will strike, causing the fuel to be equally distributed very etficiently throughout the top of the working cylinder 11.

Another feature developed by the extension of the neck 40 into the working cylinder is that the lower end of the neck is remote from the .water jacket in the cylinder head 13, Consequently, there is very little cool ing of the bottom of the neck, and the bot tom of the neck will remain hot, tendin to vaporize any liquid fuel particles, w ich may not have become vap'orized in the precombustion chamber 14 on discharging the fuel from the pro-combustion chamber into the working cylinder. Because of this, it will be noted that the closer the end of the neck 40 is to the top of the piston 12, when the piston is at the top of its stroke, the warmer the end of the neck will remain because of the lack of cooling by the water jacket. It will be readily appreciated that the improved nozzle can be used either with or without the extended neck 40. Furthermore the improved nozzle may be con structed in various other manners. The channels 36 and 38 may be formed by means of sawcuts or the like, but their particular formation is immaterial. The essential c0n struction resides in the provision of a small chamber between the inlet valve 23 and the re-combustion chamber 14, and discharging uel into this chamber in such a manner that it will be caused to whirl therein, and then conveying the fuel while whirling through a conical outlet, which conical outlet may be provided by the conical aperture 32 or may even be established by forming a conical bottom on the cup, in the apex of which there is an aperture. In many instances it isadvantageous to have the conical outlet formed in the bottom 29 of the cup terminate in a cylindrical passage, so that the conical ray discharged into the pre-combus'tion c amber will not be too wide. This construction is clearly shown in Fig. 8, in which the aperture 32 is conical in the top and terminates in acylindrical passage 43. The recess 37 preferably has a flat top so that no air will attempt to collect in the chamber,

- it being understood that if an air bubble or air pocket collects in the chamber 37, the fuel will not be uniformly or evenly de livered from the chamber into the pre-combustion chamber.

From the above described construction it will be readily appreciated that a novel form of -nozzle is provided, which will discharge a conical fuel spray into the pre-combustion chamber, which conical fuel spray is homoeneous throughout, as distinguished from uel sprays in the form of a hollow cone. Furthermore, it will be readily appreciated that a novel construction for delivering fuel from the pre-combustion chamber into the workin cylinder is also provided.

It wi 1 be understood that various changes in the detail of construction may be made without departing from the spirlt or scope of the invention as defined by the appended claim.

I claim:

In an internal combustion engine having a working cylinder within which is a piston,

and a pro-combustion chamber, a neck for conveying gases from the pre-combustion chamber to the'working cylinder, said neck,

having that end which is most adjacent the working cylinder extending materially into the working cylinder so as to be adjacent the top of the piston when the piston is at the top of its stroke, said :neck having the passage therethrough adjacent the upper end comparatively arge and having an internal annular shoulder adjacent its bottom end presenting an interior conical surface from the shoulder to its lower end.

In testimony whereof I have signed my name to this specification.

EMANUEL KRETTINGEN. 

